In several reciprocal cross-infection experiments parasites were found to be significantly more adapted to their local host populations than to hosts from distant populations. We developed a metapopulation model, taking explicit account of both population densities and gene frequencies, to determine the influence of ecological and genetical parameters on the local adaptation of the parasites and on the spatial distribution of resistance and virulence genes. Our results point to the predominant effect of ecological parameters such as parasite growth rate and host and parasite migration rates on coevolutionary outcomes. In particular, the parasites are more likely to be adapted to their local host population than to allopatric hosts when the parasite migration rate is larger than the host migration rate. The opposite should be observed whenever hosts migrate more than parasites.

In the present study, we investigated the efficiency of additional wastewater treatment based on powdered activated carbon and its benefit for the ecosystem of a connected river system in the catchment area of Lake Constance, Southern Germany. We focused on the overall health status of gammarids and the integrity of the macrozoobenthic community. Samples were taken up-and downstream of a wastewater treatment plant (WWTP), as well as before and after its upgrading. The investigations showed that both sex ratio and fecundity of gammarids, as well as the macrozoobenthic community were affected by the effluent prior to the WWTP upgrade. After the upgrade, gammarids from the downstream site did not differ any longer from those collected upstream of the WWTP with respect to the investigated health parameters. Furthermore, the overall number of taxa and, particularly, the number of sensitive taxa within the macrozoobenthic community downstream of the WWTP increased considerably. Therefore, we conclude that the additional treatment with powdered activated carbon was highly efficient to improve invertebrate health and community integrity.

<p>Accelerating climate change and biodiversity loss calls for agricultural practices that can sustain productivity with lower greenhouse gas emissions while maintaining biodiversity. Biodiversity-friendly agricultural practices have been shown to increase earthworm populations, but according to a recent meta-analyses, earthworms could increase soil CO<sub>2</sub> and N<sub>2</sub>O emissions by 33 and 42%, respectively. However, to date, many studies reported idiosyncratic and inconsistent effects of earthworms on greenhouse gases, indicating that the underlying mechanisms are not fully understood. Here we report the effects of earthworms (anecic, endogeic and their combination) with or without plants on CO<sub>2</sub> and N<sub>2</sub>O emissions in the presence of soil-moisture fluctuations from a mesocosms experiment. The experimental set-up was explicitly designed to account for the engineering effect of earthworms (i.e. burrowing) and investigate the consequences on soil macroporosity, soil water dynamic, and microbial activity. We found that plants reduced N<sub>2</sub>O emissions by 19.80% and that relative to the no earthworm control, the cumulative N<sub>2</sub>O emissions were 17.04, 34.59 and 44.81% lower in the anecic, both species and endogeic species, respectively. CO<sub>2</sub> emissions were not significantly affected by the plants or earthworms but depended on the interaction between earthworms and soil water content, an interaction that was also observed for the N<sub>2</sub>O emissions. Soil porosity variables measured by X-ray tomography suggest that the earthworm effects on CO<sub>2</sub> and N<sub>2</sub>O emissions were mediated by the burrowing patterns affecting the soil aeration and water status. N<sub>2</sub>O emissions decreased with the volume occupied by macropores in the deeper soil layer, whereas CO<sub>2</sub> emissions decreased with the macropore volume in the top soil layer. This study suggests that experimental setups without plants and in containers where the earthworm soil engineering effects via burrowing and casting on soil water status are minimized may be responsible, at least in part, for the reported positive earthworm effects on greenhouse gases.</p>

Steel production generates great amounts of by-products as steel slag. Unlike blast furnace slag, the use of Basic Oxygen Furnace slag (BOF slag) has been restrained due to insufficient volume stability and to the lack of environmental regulations. This study aimed at investigating the potential release and impact of pollutants, especially Cr and V that are present in rather high concentrations in slag, from a BOF slag used in a civil engineering structure (an industrial platform), using a multi-scale approach. The oneyear follow up of the experimental platform showed that concentrations of Cr and V were generally low in seepage waters, and in leachates from leaching test. Microanalyses carried out on slag allowed us to confirm the location of these metals in rather stable ferrous mineral phases, but V was also bound to more reactive silicates. No real toxicity effect of seepage waters has been revealed from eco-toxicological tests carried out with earthworms. La fabrication de l’acier s’accompagne d’une production d’importantes quantités de co-produits, les laitiers d’aciérie. Contrairement aux laitiers de haut-fourneau, l’utilisation des laitiers d’aciérie de conversion (laitiers LD) a été limitée en raison de leur instabilité volumique et de l’absence de réglementation environnementale. L’objectif de cette étude est d’étudier le relargage potentiel et l’impact des polluants, plus particulièrement de Cr et V qui sont présents à des concentrations assez élevées dans les laitiers, par un laitier LD utilisé dans une structure de génie civil (plateforme industrielle) à l’aide d’une approche multi-échelles.